Die



June 21, 1960 .1. E. CHENEY 2,941,245

DIE

Filed Oct. 20, 1955 Fig. 3.

Pig. 2.

n 1 "III In ven'or: dames E. Cheney,

/-//'s Attorney.

United States atent '0 DIE James E. Cheney, Scotia, N.Y., assignor to General Electric Company, a corporation of New York Filed Oct. 20, 1955, Ser. No. 541,722

5 Claims. (Cl. 18- 16.5)

"This invention relates to dies and more particularly to such dies which are employed in high temperature high pressure apparatus.

In a copending application of Francis P. Bundy, Serial 'No. 488,042, filed February 14, 1955, and assigned to the same assignee as the present application, an apparatus 'is described and claimed to eifect and control reactions which occur at temperatures of the order of several :thousand degrees Centigrade and pressures of 20,000 to 40,000 atmospheres for long time intervals. Such apparatus comprises a reaction vessel which is positioned be- :tween a pair of opposed, recessed dies with annular lips fto provide a specimen chamber to be subjected to temperatures and pressures of the order mentioned.

In previous apparatus, die stroke was limited by opposing die lips which were necessary to prevent lateral ex Til'llSlOIl of the reaction vessel. The problem was overcome partially by a gasket assembly which increased the :size of the reaction vessel to produce a more effective die :s'troke. However, the invention of the present application provides a novel die having additional stroke which eliminates such a special gasket assembly.

Accordingly, it is an object of my invention to provide a new and improved die.

It is another object of the invention to provide an improved die for high pressure high temperature apparatus.

It is another object of the invention to provide an improved die which produces higher pressures by increasing the effective die stroke.

It is a further object of the invention to provide an improved die which operates as a two-stage die in a single stage press.

In carrying out my invention in one form, a hollow casing has an apertured die face at one end and a slidable force block within the, other end to enclose a central core surrounded by a volumetric transitional material to provide a die.

These and various other objects, features and advantages of the invention will be better understood from the following description taken in connection with the accompanying drawing is which:

Fig. 1 is a sectional view of a die which embodies my invention; and

Fig. 2 is a partial sectional view of a high pressure high temperature apparatus which employs the die of Fig. 1.

In Fig. l of the drawing, a die is shown which com- ;pn'ses a generally hollow casing, such as, a cylinder 11 with an integral closure 12 at one end. The outer face of closure 12 is tapered outwardly toward the longitudinal axes of the closure 12 and the cylinder 11 and then tapers inwardly toward aperture 14 thus forming an annular lip 13 which surrounds a central aperture 14 in .closure 12. A core or pin 15, which has a flat face 16 and hemispherical face 17, is positioned partially within aperture 14. Flat face 16 is positioned normally at the base of lip 13 within aperture 14. A washer 18 of volumetric :transitional material is positioned between core and the inner wall of cylinder 11 to surround partially the core. A material of this type undergoes a phase transition which reduces its volume when the pressure reaches and exceeds its critical value. A force block or piston 19 with a recess 20 on its inner surface slidably fits partially within the open end of cylinderll. Recess 20 seats face 17 of core 15 while a portion of block 19 projects beyond the outer edge of cylinder 11.

When a force is applied to a die by a pressure source, such as, a hydraulic press, the die will transmit this force against a specific object. If it is desired to increase the force which is applied against the object, it is necessary to increase proportionally the press load. However, I have found that the force can be increased without a similar increase in press load when a two-stage die is employed which has a washer of volumetric transitional material between its face and its force block.

Volumetric transition contemplates or includes a sharp and distinct volume change of a material undergoing compression. For the purpose of explanation, an exaggerated curve is shown, in Fig. 3, of a material which will not undergo such a transition. In Fig. 3, the curve for material A undergoing compression, shows a generally proportional reduction in volume for increases in pressure. In Fig. 4, there is shown a material B, which undergoes a volumetric transition. A curve for material B discloses a partial generally proportional reduction in volume from the points C to D. At the point D, however, an increase in pressure results in a sharp reduction in volume to the point B, and thereafter, an additional proportional volume reduction to the point P. The part of the curve represented by the points D and E is the volumetric transition as defined for the purposes of this invention. The process is generally reversible in that the material will also follow the curve from points F to C.

A number of materials undergo volumetric transitions at elevated pressures whereby the material occupies a smaller volume at and above this point. While it may be seen that numerous volumetric transitional materials may be employed in this invention, more satisfactory results are obtained from solids rather than liquids or gases. Examples of suitable materials which can be used for washer 18 of the present invention are calcium carbonate (CaCO cuprous iodide (Cu I potassium cyanide (KCN), lead iodide (Phiammonium formate (HCO NH and urea (CH ON The diameter of washer 18 determines the press load which is necessary to cause the volumetric transition while the thickness of the washer determines the amount of additional stroke available.

Die 10 is assembled by inserting core 15 into aperture 14 of closure 12 so that core face 16 is positioned at the base of lip 13. A washer 18 of volumetric transitional material which has a central aperture is positioned around core 15 to fit against the inner wall of cylinder 11. Force block 19 is then positioned within the opposite end of cylinder 11 to seat core face 17 in recess 20. A portion of force block 19 projects beyond the outer edge of cylinder 11 to provide a member against which pressure is actuated by only a single stage pressure source, such as,

a hydraulic press. In Fig. 2, die 10 is shown in a high temperature high References Cited in the file of this patent UNITED STATES PATENTS 1,918,064 Taylor July 11, 1933 2,122,960 Schwartzwalder July 5, 1938 5 2,125,068 Dempey July 26, 1938 2,127,994 Davis et a1. Aug. 23, 1938 2,195,297 Engle Mar. 26, 1940 2,360,528 Talmage -Q. Oct. 17, 1944 2,544,414 Bridgman et a1 Mar. 6, 1951 10 2,694,922 Vilella Nov. 23, 1954 OTHER REFERENCES Bridgman: J. of Chem. Physics, vol. 15, pages 92-98, February 1947. (Copy in Scientific Library.) 23 /209.1-D.

Bour et al.: *Zeitschrift fur Anorganische Chemie, v01. 92, pages 324-328 (1915). (Entire article includes pages 313-328.) Copy in Scientific Library.

Bridgman IV: Review of Modern Physics," vol. 18. No. 1, Pp. 1-9. 19-27, 32-38, 79-88, 1946. (Copy in Sci. Lib. QCl R 45.)

Bridgman III: Am. Acad. of Arts and Sciences, Proceedings, v01. 74, No. 3, pp. 21-28, October 1940. (Copy in Sci. Library, Q11 B7.)

Parsons: Philosophical Transactions of the Royal Society, vol. 220, pages 67-71, 92-99, 1919, Series A. (Copy in Sci. Lib. 23/209.l-d.) 

